The invention relates to a telephone index with an index card selection device, comprising a housing having a cover part and a base part with a plurality of selection keys and with a drawer under the action of a pretensioned spring and which can be closed by means of a locking device for receiving a stack of a plurality of index cards with selection stampings formed in the front region, whereby when the selection keys are operated by means of card hold-back pins they engage in selection stampings of the index cards on extending the drawer with the selected index card and the index cards located below it, drivers on the bottom of the drawer for engaging the selected index card and the underlying index cards on extending the drawer and a device controllable by means of selection keys for releasing the locking device for the drawer. Numerous different constructions are known of telephone indexes with selection devices. They comprise a housing for receiving a stack of loose index cards and a keyboard with correspondingly marked finger keys, whose operation makes it possible to select the desired cards. Random instructions or notes for subsequent reference purposes can appear in alphabetical order on the index cards.
A telephone index is known, which comprises a housing having a drawer under the action of a thrust spring and closed by a bolt for receiving the index cards and with a device for unlocking the drawer and releasing the index cards selected by means of a set key through the unlocked drawer being pressed down by means of the thrust spring.
Furthermore, DE-A-23 06 961 discloses a device for selecting one of many cards stored in a housing, which are selected by key pressure and re horizontally stacked in a drawer, arranged in an opening in the front wall of the housing and being horizontally slidable into the housing in a closed position and out of the housing in an open position and in which they are locked against pretension. For this purpose a latch is provided with a clip member, which is movable fixed and pretensioned in the housing and engages in a notch in the drawer. A key lever is provided for each card and has a rod pivotably fixed in the housing, whereby one end of the lever carries a manually operable key located outside the housing, whereas the other lever end is on the one hand provided with a shoulder for unlatching the clip member from the drawer on operating the key and on the other hand has a shoulder which so cooperates with the cards having aligned recesses, that on pressing down the key all the cards located above that card associated with said key are prevented from moving with the drawer, whereas the selected card and all cards below it can be moved out with the drawer. In the case of said known telephone indexes a number of card drivers or dogs corresponding to the number of cards is pivotably articulated to the drawer and which by means of shoulder positioned at the key lever end opposite to the key can be moved into an engaged position on the rear edge of the selected and underlying cards on pressing down the corresponding key, whilst the shoulder cooperating with the cards is constructed in such a way that it simultaneously engages in a recess of all cards located above the selected card to prevent movement thereof.
In another telephone index known from FR-A-1 569 217, the cards located above the selected card are engaged and raised on the trailing edge thereof by a shoulder of the associated key lever on pressing down a particular key, so that the cards together with their recesses are guided over a holding projection on the housing cover. Said projection secures the raised cards, whilst the remaining cards free on the bottom of the drawer are carried along by the outwardly moving drawer and for this purpose are positionally secured on their trailing edge by a projection on the bottom of the drawer. On releasing the key the rod of the key lever is immediately pivoted back, so that the previously raised cards with their recesses are again freed from the holding projection on the housing cover. In this construction the two-armed selection lever has on its one arm end the operating key and on its other end a section bent in the direction of the front of the device, which engages below the card stack above the selected card and raises the same and simultaneously a holding nose shaped onto the inner wall of the upper housing cover engages through an opening in the rear lever arm, through the aligned openings of the raised card stack and in a slot-like opening in the bent section. As a result of this construction, it is ensured that unselected index cards located above the selected card are held back on extending the selected card with the cards positioned below it. This telephone index also operates with a clip member, which can be brought into operative engagement with a shoulder shaped onto the rear lever arm end when the corresponding selection lever is operated. By means of this clip member the arresting action for the drawer is released, so that the drawer with the selected index card and the card stack located below it can be extended.
In a telephone index known from US-A-3 818 622, the card hold-back pin of each pivoted lever comprises a roughly U-shaped portion shaped onto the end of the lever with a leg running towards the selection keys and with a vertical, upwardly directed bar shaped onto its end and which on operating a pivoted lever engages from below in the index card openings or recesses. Here again a separate device is provided which cooperates with the hold-back pin to ensure that the index cards above the selected card to be extended are satisfactorily held back.
DE-A-27 41 138 discloses a telephone index with an index card selection device, comprising a housing having a cover part and a base part with a plurality of serially juxtaposed and superimposed selection keys and a drawer under the action of a compression spring and closable by means of a locking device, with a stack of index cards housed therein which have selection tongues in their rear edge portions, together with openings, whereby the tongues are enlarged in step-like manner from the card with the first opening from on side to the other to the overlying card by in each case one selection tongue carrying an opening. Each selection key is fixed to one end of a pivoted lever, which carries at its other end a card hold-back pin, which has an approximately U-shaped portion shaped onto the pivoted lever end with a leg directed towards the selection keys and on the end thereof a vertical, upwardly directed bar which on operating the pivoted lever engages from below into the index card openings or recesses. The card hold-back pins of the pivoted lever are arranged in series and cooperate with the index cards in such a way that on pressing down one selection key, all the index cards located above the card associated with said key are held back on moving out the drawer through the insertion of the card hold-back pins into the openings of the selection tongues of the cards, whilst the selected index card and all those cards located below it are moved out with the drawer. There is also device operable by means of the pivoted levers of the selection keys for unlocking the drawer and which comprises a clip member articulated to the housing, the web of said member running transversely to the longitudinal direction of the pivoted lever rests thereon above the latter and is subjected to the action thereof and which cooperates with a cam shaped onto the drawer in such a way that on raising the clip member on operating a selection key the locking part of the clip member is disengaged from the cam, so that the drawer, provided with driving cams for engaging in driving stampings of the cards is extended by means of spring tension. This telephone index is characterized by the combination of the following features. The selection keys of the pivoted levers comprise plate-like, square or rectangular blanks fixed to first ends thereof, whereby the serially succeeding selection keys have a width corresponding to the width of in each case three pivoted levers carrying the keys and which are connected therewith in such a way that the selection key facing the hold-back pins on the rear ends of the pivoted levers project over to the right the two adjacent pivoted levers and the front selection key pivots to the left over the two adjacent pivoted levers and the central selection key engages to the right and left over the pivoted levers on either side of said selection key. The vertically upwardly directly bar of each card hold-back pin has a cam-shaped shoulder running parallel to the leg of the U-shaped portion of the hold-back pin. The drawer comprising a plate-like drawer bottom and a front terminal ledge or strip closing the drawer extension opening in the housing front wall when the drawer is inserted is open at the back and on either side and is provided in its rear edge region with a number of slot-like recesses corresponding to the number of hold-back pins with a length corresponding to the length of the U-shaped portions at the ends of the pivoted levers. The two lateral drawer boundary walls are formed by two walls on either side of the plate-like drawer bottom and shaped onto the inner wall surface of the housing cover part. For guiding the pivoted levers, each pivoted lever is provided on the end carrying the card hold-back pin with a vertically directed, slot-like opening, in which engages a cam shaped onto the inner wall surface of the housing cover part and is guided in opening. In summarizing it is pointed out that the known selection devices of telephone indexes have a very complicated construction, because the number of key levers corresponds to the number of selection keys and they carry card hold-back pins so as to permit a selection of the index cards. In addition, the known telephone indexes comprise a plurality of components, so that index assembly is labour-intensive and costly. In order to ensure that when operating the selection keys the unselected index cards remain in the housing on extending the drawer with the selected index card and those cards located beneath it, the cards are provided with hole-like openings, in which engage card hold-back pins. When such telephone indexes are frequently used, these hole-like openings become deformed. The edge regions of the openings are damaged, tear and consequently incorrect operations often occur. In addition, further driving stampings are provided in the index cards and they are generally in the form of hole or slot-like openings in said cards, so that driving cams shaped on the drawer bottom can engage therein so that, on extending the drawer, the selected index card and the underlying index cards are engaged and supplied with the extending drawer. These driving stampings in the index cards are also subject to damage.
The problem of the invention is to provide a telephone index comprising very few parts, so that there are very short assembly times and the manufacture of the telephone index is very inexpensive, in which the index cards do not have to be used in a predetermined order and in which there is no need for additional locking and unlocking devices, the locking and unlocking of the drawer with the index card stack taking place by drawer position changes.